Pitman structure



Nov. 19, l1929. R. R. BLoss PITMAN STRUCTURE IIN HIIIHHHMIIXII'.

Filed Aug. 16. 192B ,pag.4

IN1/EN ToR.

l/WI- ATTORNEYS.

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Patented Nov. 19, 1929 UNITED STATES PATENT orsi-es RICHARD B.. BLOSS, OF COLUMBUS, OEO', ASSIGNOR TQ :INTERNATIONAL DERRCK & EQUPMENT COMPANY, OF COLUIvBU'jS, OHIO, A .CORPGRA'ION OF O-I'O Piratenv sTnUoTunn Application filed` August.1 6,'1928.' Serial No. 300,114.

My invention relates to pitman structure. lt is particularly useful in connection vwith oil, gas and artesian wells, although not necessarily limited thereto. y j

One of the objects of this invention is to reduce to a minimum the shocks and impacts which are transmitted through the apparatus for operating` the drilling or pumping mechanism commonly used inthe drilling of wells of the type in question. The pitman is ordinarily used to connect the wrist pin ofV the crank to the end of the walking beam, the other end of the walking beam being` con'- nected either to the sucker rod on a producin@ well or to the temper screw on a drilling well. In either event, these parts are subjected to very severe shocks and impacts.

Another object of my invention is to pro-r vide a pitman structure which embodies a bearing separable into sections andl whichk also embodies adequately yieldable portions but which is so designed that its parts will not be loosened or displaced from proper operative position due to vibration ofthe movable parts.

Another object of my invention is toprovide a bearing structure formed in sections which may be held in proper operative relation but which, when released, are 'automatically separable to facilitate ready reception or removal of the wrist-pin of the crank.

The preferred embodiment of my inven` tion is shown in the accompanying drawings wherein similar characters of reference designate corresponding parts and wherein:

Figure 1 is a front elevation of the lower portion of my pitman structure.

Figure 2 is a side view of the structure shown in Figure l.

Figure 3 is a front elevation of my base casting` shown removed from my pitman structure.

Figure 4 is a front elevation of my bearing cap shown removed from my pitman structure.

Figure 5 is a front elevation of my lower bearing section.

ln the drawings, my pitman structure is shown as comprising a Ll-shaped bottom portion 1 which has its leg extremities connected to` an I-beam portion Zby -means of rivets 3. Fitted within the rounded contour of the bottom Vendl of the pitman shank is a base casting 4 which is likewise rounded and conforms to the internal contour of this bottom end. This base casting,` 4 is `preferably secured in place by a bolt 5. 4

Mounted uponthe--upper end of the base casting 4 is an elastic pad of rubber or other material which is'designated 6. This elastic pad is designed to fit into a recess or socket 7 in the base of a section 8. rllhe section 8 fits slidablybetween the legs of the Ushaped member 1 and is provided on its middle portion with a bearing seat 9 having a lining of babbitt or other bearing material 10.

Superimposed upon the casting 8 is a bearing cap 11 which is provided 'in its under surface with a recess 12. This recess 12 is also lined with babbitt or other bearing material as at 13 and is complemental to the babbitt lined recess 9 so as to form a bearing` for the wrist-pin of the crank. *The bearing cap 11 is normally held in lowered orv operative position by means of a wedge 14 which extends through an opening 15 in the bearing cap. This opening preferably has its upper side horizontal as at 16 but its lower side is inclined as at 17 so that it substantially conforms to the lower inclined side 18 of the wedge 14. rlhis wedge ymay be' further provided with a pin 19 in its ysmaller end for normally preventing complete removal of the wedge member from the -pitman-y d y A set screw 20 is threaded into the bearing 'cap 11 and yis provided with a lhandle 21.

rlhisfset screw extendsA through the wall of the opening 15 in the bearing cap and is designed to make contact with the side of the wedge 14. By tightening the set screw, it vmaybe forced to bear against the wedge member 14 so as to hold it in any desired position. lt is normally used to maintain thewedge in Vsuch a position that the bearing cap is in operative relation to the section 8, to avoid 'loosening ofthe wedge and the bearing cap by vibration oi the moving parts.

A 'means is provided for automatically 4lifting the bearing cap 11 out' of` operative relation upon withdrawal of the wedge. This means preferably comprises a hook bolt 22 which is hooked through a pierced lug 23 carried upon the upper end of the bearing cap. This hook bolt extends upwardly through the yoke 24which is formed upon the upper end of the base section 8 and is provided upon its upper end with a compression spring 25. This compression spring is held upon the hookbolt by means of a nut 26, being disposed between this nut and the upper surface of the yoke 24'.

In operation, this compression spring 25 normally exerts an upward pull upon the bearing cap 11. When the wedge 14 is withdrawn from its innermost position, the spring 25 exerting its upper pull upon the hook bolt 2O serves to lift the bearing cap so thatl the'bearing may be easily removed from or placed upon the wrist-pin of the crank.

My pitman structure is also several accessory features. One of these features comprises an oil well 27 in the upper part of the bearing cap 11. Access is had to this oil well by means of a flap 28 hinged as at 29. The pitman is further provided with a handle 30 adjacent its lower end. This handle comprises a U-shaped member having its legs passing through apertures 81 in the lower end of the base casting 4 and secured in position therein by means of nuts 32.

In operation, the base section 8 is free to move in the member 1 through a limited distance. When the load is applied against the bearing recess of this base section, thissection is moved downwardly so that the force of this load is transmitted to the base of the pitman through the compressible material 6. This reduces to a minimum the force of the impact caused by the movement of the wrist-pin and the acceleration of the sucker rods or drilling tools. When the pitman has reached its extreme downward position and the load is completely or partially removed from'the base of the pitman, the compressible material 6 expands to its original form, being again compressed at the beginning of the downward stroke. Thus, it acts as a cushion or shock absorber over a considerable period of time. Should the cushion 6 become worn or ineffective, it can be replaced readily at a very small expense.

It has already been pointed out that the application of the pitman to the wrist-pin of the crank or the removal therefrom is readily accomplished by withdrawal of the wedge member. As soon as this withdrawal occurs, the bearing cap 11 is automatically drawn away from the lower portion of the base section 8 so as to increase the area of the bearing, aplication or removal thereby being facilitated.

provided with v It will be apparent that I have provided a Vpitman structure which is of rigid construction but which is, nevertheless, of such form that the shocks and impacts will be practically absorbed. Likewise, the structure is such that the pitman may be removed or applied with a minimum of difculty.

Having thus described my invention,- what I claim is:

1. A pitman structure for oil, gas and artesian well drilling and pumping mechanism comprising a U-shaped base portion, a supporting member disposed within the bottom of said U-shaped base portion, a resilient member carried upon said supporting member, a bearing section resting upon said resilient member, said bearing section having a yoke carried upon its upper end, and a bearing cap member disposed within said yoke. t Y 2. A bearing structure for oil, gas and artesian well drilling and pumping mechanism comprising a body portion, "a supporting member carried at the base of said body portion, a resilient block carried upon said supporting member, a base casting sup ported by said resilient block and having a socket in its lower end for enclosing said block, an upstanding yoke upon the upper end of said base casting, a bearing recess in the upper end of said base casting, a bearing cap member fitting within. said yoke, said cap member having a complemental recess therein, means for maintaining said bearing cap member in operative position, and a resilient. connection between said bearin cap member and the upper end of said yo e to eii'ect withdrawal of said bearing cap member when said last-named means is rendered inoperative.

In testimony whereof I hereby aiiix my signature.

` RICHARD R. BLOSS. 

